Precured fibrous elements for a spar cap of a wind turbine blade

Abstract

A wind turbine blade part includes a plurality of precured fibrous elements each having a width defined between a first side and an opposite second side, a thickness defined between an upper surface and an opposite lower surface, a length defined by a first longitudinal end and a second longitudinal end, and a longitudinal direction extending between the first longitudinal end and the second longitudinal end. Each precured fibrous element includes a plurality of unidirectional fiber bundles extending substantially in the longitudinal direction of the precured fibrous element and at least one non-woven fiber strip. The plurality of unidirectional fiber bundles and the at least one non-woven fiber strip are embedded in a polymer matrix. The non-woven fiber strip is arranged between a plurality of first unidirectional fiber bundles and a plurality of second unidirectional fiber bundles of the plurality of unidirectional fiber bundles.

1 - 15 . (canceled) 
     
     
         16 . A wind turbine blade part, comprising:
 a plurality of precured fibrous elements, wherein each of the plurality of precured fibrous elements has:
 a width defined between a first side and an opposite second side; 
 a thickness defined between an upper surface and an opposite lower surface; 
 a length defined by a first longitudinal end and a second longitudinal end; and 
 a longitudinal direction extending between the first longitudinal end and the second longitudinal end, 
   wherein each of the plurality of precured fibrous elements comprises:
 a plurality of unidirectional fiber bundles extending substantially in the longitudinal direction of a respective one of the plurality of precured fibrous elements; and 
 at least one non-woven fiber strip, 
 wherein the plurality of unidirectional fiber bundles and the at least one non-woven fiber strip are embedded in a polymer matrix, and 
 wherein the at least one non-woven fiber strip is arranged between a plurality of first unidirectional fiber bundles and a plurality of second unidirectional fiber bundles of the plurality of unidirectional fiber bundles. 
   
     
     
         17 . The wind turbine blade part of  claim 16 , wherein the at least one non-woven fiber strip is arranged to form at least a first layer, wherein the first layer is arranged between the plurality of first unidirectional fiber bundles and the plurality of second unidirectional fiber bundles. 
     
     
         18 . The wind turbine blade part of  claim 17 , wherein each of the plurality of precured fibrous elements comprises a plurality of non-woven fiber strips, comprising the at least one non-woven fiber strip, and wherein the plurality of non-woven fiber strips is arranged to form a plurality of separate layers, and
 wherein each of the plurality of separate layers is arranged between the plurality of first unidirectional fiber bundles on a first side of a respective one of the separate layers and the plurality of second unidirectional fiber bundles on a second side of the respective one of the separate layers.   
     
     
         19 . The wind turbine blade part of  claim 17 , wherein the first layer extends substantially from the first side to the second side of the plurality of precured fibrous elements. 
     
     
         20 . The wind turbine blade part of  claim 17 , wherein the first layer extends substantially from the upper surface to the lower surface of the plurality of precured fibrous elements. 
     
     
         21 . The wind turbine blade part of  claim 16 , wherein the at least one non-woven fiber strip is arranged to have an oblique angle as seen in a cross-section view of the plurality of precured fibrous elements. 
     
     
         22 . The wind turbine blade part of  claim 16 , wherein the at least one non-woven fiber strip is arranged to form a zig-zag pattern as seen in a cross-section view of the plurality of precured fibrous elements. 
     
     
         23 . The wind turbine blade part of  claim 16 , wherein the at least one non-woven fiber strip comprises randomly oriented fibers. 
     
     
         24 . The wind turbine blade part of  claim 16 , wherein the at least one non-woven fiber strip has a thickness between a first non-woven fiber strip surface and a second non-woven fiber strip surface, wherein the thickness is between 0.001-2.0 mm. 
     
     
         25 . The wind turbine blade part of  claim 16 , wherein the at least one non-woven fiber strip has a width between a first non-woven fiber strip side and a second non-woven fiber strip side, wherein the width is between 1-300 mm. 
     
     
         26 . The wind turbine blade part of  claim 16 , wherein each of the plurality of precured fibrous elements are stacked in an array. 
     
     
         27 . A method for manufacturing a wind turbine blade part for a wind turbine blade, the method comprising:
 providing a plurality of precured fibrous elements;   stacking the plurality of precured fibrous elements in an array such that interface regions are formed between adjacent precured fibrous elements of the plurality of precured fibrous elements;   supplying resin to the plurality of precured fibrous elements and causing the resin to fill the interface regions between the adjacent precured fibrous elements of the plurality of precured fibrous elements; and   curing the resin to form the wind turbine blade part,   wherein each of the plurality of precured fibrous elements has:
 a width defined between a first side and a second side; 
 a thickness defined between a first surface and a second surface; 
 a length defined by a first longitudinal end and a second longitudinal end; and 
 a longitudinal direction extending between the first longitudinal end and the second longitudinal end, 
   wherein each of the plurality of precured fibrous elements comprises:
 a plurality of unidirectional fiber bundles extending substantially in the longitudinal direction of a respective one of the plurality of precured fibrous elements; and 
 at least one non-woven fiber strip, 
 wherein the plurality of unidirectional fiber bundles and the at least one non-woven fiber strip are embedded in a polymer matrix. 
   
     
     
         28 . A precured composite fibrous element for a load-carrying structure of a wind turbine blade, the precured composite fibrous element comprising:
 a width defined between a first side and a second side;   a thickness defined between a first surface and a second surface;   a length defined by a first longitudinal end and a second longitudinal end;   a longitudinal direction extending between the first longitudinal end and the second longitudinal end;   a plurality of unidirectional fiber bundles extending substantially in the longitudinal direction of the precured fibrous element; and   at least one non-woven fiber strip,   wherein the plurality of unidirectional fiber bundles and the at least one non-woven fiber strip are embedded in a polymer matrix.   
     
     
         29 . A method for manufacturing a precured composite fibrous element for a load-carrying structure of a wind turbine blade, the method comprising:
 drawing a plurality of unidirectional fiber bundles and at least one non-woven fiber strip through a resin tank and a pultrusion die to form a precured fibrous element comprising:
 a width defined between a first side and a second side, 
 a thickness defined between a first surface and a second surface, 
 a length defined by a first longitudinal end and a second longitudinal end, and 
 a longitudinal direction extending between the first longitudinal end and the second longitudinal end, 
 a plurality of unidirectional fiber bundles extending substantially in the longitudinal direction of the precured fibrous element, and 
 at least one non-woven fiber strip, 
 wherein the plurality of unidirectional fiber bundles and the at least one non-woven fiber strip are embedded in a polymer matrix.